In machine construction, for example, in an assembly installation, linear guidance systems are known that work in the vertical direction. In the process, the components to be moved, which may be very heavy, are moved up and down preferably in the vertical direction. To secure the moved loads, for example, in the case of a system failure with pressurized air stoppage or electrical power outage, clamping systems are known in practice that are capable of clamping the load to be carried in a substantially arbitrary vertical position relative to a guide, so that the load is not lowered or does not fall due to gravity.
In particular, clamping systems are known in which a clamp element is provided with a chamber into which a medium can be admitted, which chamber, during the admission, undergoes changes in its geometric dimensions such that, as a result, a force is applied or released against a stationary component relative to the moved load, to allow a clamping or release of the relative movement between the load and the component. This stationary component can be particularly the vertical guide. Usually pressurized air or hydraulic oil is admitted into the chamber.
In particular, there is a known design of a clamping system that, in the pressureless state (when there is no pressure in it), generates a clamping force, which design as a result of the pressure admission caused by a corresponding deformation of the chamber releases the clamping force and allows the relative movement between the weight-bearing part and the fixed component. This system presents the advantage that in the case of a stoppage of the pressurized air or the corresponding hydraulic medium, the clamping force is applied, and the relative movement is stopped, preventing further movement of the weight in the case of a system failure.
However, the disadvantage of the designs known from the state of the art is that, following a failure as described above, the connection of the corresponding medium results in the clamping force being released again, and the weight being again set in motion as a result of gravity. This can cause considerable harm, both to equipment and to humans, if the connection of the medium occurs without sufficient consideration or safety provisions for the possible subsequent movement of the weight. The safety mechanism thus works only to the extent that a failure of the system pressure stops a relative movement. The consequences of reestablishing the system pressure are the responsibility of only the operating personnel and are thus associated with risk.
The problem of the invention therefore is to provide a safety device that allows a reliable new startup of the above-mentioned installations, and that has a construction that is simple and cost-effective to carry out.